In order to record the rotary speed and angle, especially the crankshaft angle and/or camshaft angle of an internal combustion engine, incremental gears are used. An incremental gear has marks on its circumference which are ideally affixed at equidistant angular distance. The incremental gear is scanned by a sensor element. A post-connected slope evaluation detects the position of the marks from the sensor signal.
However, the actual crankshaft angle is recorded only inaccurately by the marks of the incremental gear. Among other things, the tolerances of the incremental gear (the effective, not equidistant signal-generating wheel marks), of the sensor and the slope evaluation invalidate the angle thus recorded.
Methods are known for adapting the tolerances of the signal-generating wheel and the angular recording (German Published Patent Application No. 42 16 058).
Since a nonuniform rotary motion of the engine is created by compression and expansion of the aspirated air in the cylinders, even in overrun condition, the known adaptation algorithms require models which describe the irregularity with respect to rotation of the engine. After the separation of these signal portions from the measured signal, the signal portions caused by the tolerances of the signal-generating wheel or the angle recording are left over.
By evaluating the left-over signal portions, for instance, according to German Published Patent Application No. 42 16 058, equidistant angle marks cannot be detected and subsequently used for compensating the angle errors. Since the models of the irregularity with respect to rotation of the engine are only conditionally accurate, however, the separation of the signal portions described is only approximately possible. Because of this, there is a residual error for the position of the angle marks.
Furthermore, methods are known of recording and regulating individual parameters of the combustion process in an internal combustion engine, using combustion chamber pressure sensors.